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Complex analysis of VLF wave phenomena recorded on CHIBIS-M LEO satellite

Complex analysis of VLF wave phenomena recorded on CHIBIS-M LEO satellite. FERENCZ, Csaba (1) , † BODNÁR, L ászló (2), STEINBACH, Péter (1,3) , SZEGEDI, Péter (2) , LICHTENBERGER, János (1), E. FERENCZ, Orsolya (1) , HAMAR, Dániel (1)

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Complex analysis of VLF wave phenomena recorded on CHIBIS-M LEO satellite

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  1. Complex analysis of VLF wave phenomena recorded on CHIBIS-M LEO satellite FERENCZ, Csaba (1) , † BODNÁR, László (2), STEINBACH, Péter (1,3), SZEGEDI, Péter (2), LICHTENBERGER, János (1), E. FERENCZ, Orsolya (1), HAMAR, Dániel (1) 1 Space Research Group, Eötvös Univ.,Dept. of Geopysics and Space Sci., Budapest,Hungary,spacerg@sas.elte.hu,+361 372 2906 2 BL ELECTRONICS, Solymár, Hungary 3 MTA-ELTE Research Group for Geology, Geophys. and Space Sci (HAS), Budapest, Hungary

  2. PSA-SAS3 VLF waveform recordings 2012.03.01-2012.12.03 ~850 burst data segment E electric – ch0 Bz magnetic – ch5 Fs=39062.5Hz

  3. Bodnár László 1961-2012

  4. CHIBIS-M E-field ch0 2012.10.20 12:47:08 UT+3 3:50 LT 270.9E 19.24N geographic mlat 30.3N geomagnetic D0 dispersion: 1.8 s½ CHIBIS-M Bz ch5 2012.07.21 23:22:20 UT+3 3:33 LT 107.8E 2.6S geographic mlat 11.5S geomagnetic D0 dispersion: 2.5 s½ CHIBIS-M E-field ch0 2012.10.24 06:25:01 UT+3 3:13 LT 317.1E 4.8N geographic mlat 0.8S geomagnetic D0 dispersion: 14.5 s½

  5. Hughes and Rice, JASTP, 59, 10, 1997 ● whistlers crossed the ionosphere fall in two distinct classes ● their dispersion values strongly depend on magnetic latitude of the satellite, (and on other factors, like LT too…) Δ day ○ night

  6. DAYTIME PASS NIGHTTIME PASS

  7. global lightning map 1month averaged VLF wave intensities along LEO (660km) orbits DEMETER ICE VLF spectrum data, nighttime passes frequency band: 6-15.5 kHz, VLF transmitter bands removed

  8. Determination of most probable sferic entry point at the bottom of the ionosphere oblique UWB code IRI2007 IGRF10 Comparison of modeled, trans-ionospheric whistler traces to recorded one. -> geographic distribution of residuals (similarity values), and best fit entry point at residual minima; latitude dependent topology of prop. in the ionosphere

  9. L=1.08 equator very simplified cartoon for VLF wave propagation in the ionosphere ● waves reach the satellite along paths with minimum propagation time; this is represented by the path between the shortest, but high angle (vertical) and the longer, field aligned (longitudinal) directions

  10. L=1.08 equator intropical regions the magnetic field governed propagation topology is symmetric ● at equatorial and low magnetic latitudes occurrences of fractional-hop whistlers with two dispersion classes are expected

  11. low-latitude whistler pairs, CHIBIS-M, electric sensor (ch0) 2012.12.01. 18:51:03UT 93.48E;8.87N L=1.08

  12. A B C low-latitude whistler triplet pair, CHIBIS-M, electric field sensor (ch0) 2012.09.19. 00:50:31UT+3 267.79E;23.24N mlat=33.91 L=1.56 calculated D0 dispersions are A: 1.8 s½, B: 10.8 s½, C: 21.2 s½

  13. CHIBIS-M ch0 2012.07.21 23:23:38UT+3

  14. CHIBIS-M ch0 2012.07.21 23:23:35UT+3 110.41E;1.18N, mlat: 6.64S

  15. published phenomenon: swallow-tailed whistlers described in DEMETER burst records [Ferencz et al., JGR,115,2009JA014636] DEMETER VLF electric waveform data

  16. STW accompanied to short-path fractional hop (0+) whistlers; D0=2.7 s½ First observation proving that the generation mechanism, source region of STWs is located within the ionosphere.

  17. Case studies of amplitude modulation of whistler waves #1: closely spaced oblique traces CHIBIS-M ch5 Bz 2012.11.11 07:03:37 UT+3 49.90E; 20.65S D0=22.9 s½

  18. ● Matched filtering yields high-resolution amplitude pattern ● Fine structure refers to source and medium (path) characteristics one whistler trace 2.8ms 6.4ms

  19. Case studies of amplitude modulation of whistler waves #2: effect of double impulse excitation E field - ch0 Bz field – ch5 calculated CHIBIS-M 2012.11.13 18:08:13 UT+3 76.38E;11.73S modulation pattern of quasi equidistant minima can be modeled as double-dirac excited impulse dt=256µs

  20. Case studies of amplitude modulation of whistler waves #3: effect of distant sub-ionospheric guided propagation ● real full-wave solution for guided, sub-ionospheric propagation ● arbitrary excitation (Dirac, rectangular, waveform) O.E. Ferencz et al., Ann.Geophys,25,1103,2007 Crossed-loop ground VLF recording of tweeks (on the left, Marion-Island) and modeling results of lightning excited wave propagation under and crossed the ionosphere (on the right)

  21. 3500km 500km 1500km 2500km 0 time (ms) 100 0 time (ms) 100 0 time (ms) 100 0 time (ms) 100 Varying mode pattern in calculated UWB signals, according to lightning~sub-satellite distance

  22. Fractional-hop (0+) whistlers with different intensities and modulation patterns randomly distributed lightning sources: typical case CHIBIS-M ch0 2012.10.30. 10:02:32 UT+3 262.22E;11.00N

  23. specal case: no storm activity in the large vicinity of the satettlite, except one intense thundersorm -> regular modulation pattern according to distance CHIBIS-M ch0 2012.11.05 01:13:58 UT+3 17.72E; 8.75S

  24. Decreasing satellite-storm distance CHIBIS-M ch0 2012.11.05 01:13:58 UT+3 17.72E; 8.75S

  25. known phenomenon as “V-shaped VLF streaks”above powerful thunderstorms [Parrot et al, JGR, 113, 2008JA013336]

  26. CHIBIS-M ch0 2012.10.25 04:24:54UT+3 22.59E; 3.90N

  27. CHIBIS-M ch0 2012.10.25 04:24:54UT+3 22.59E; 3.90N

  28. Large database of archived LEO satellite recordings related to TID, AGW and whistler phenomena in the ionosphere. Contributors from 5 countries (Ukraine, France, Bulgaria, Poland and Hungary) EC supported project in 2011-2013 IWS - Ionosphere Wave Service; a web based search engine on database of selected wave types DB buildup is in progress, will available in 2013, www.popdat.org (X)

  29. vanellus / lapwing / чибис / bíbic Thank you for your attention! Благодарю вас за внимание!

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